JFreeChart line chart

In this example, we will create a line chart using JFreeChart library.

JFreeChart is a popular Java library for creating charts. JFreeChart allows to create a wide variety of both interactive and non-interactive charts. We can create line charts, bar charts, area charts, scatter charts, pie charts, Gantt charts, and various specialized charts such as wind charts or bubble charts.

JFreeChart Maven dependency

For our projects, we use the below Maven dependency:

<dependency>
    <groupId>org.jfree</groupId>
    <artifactId>jfreechart</artifactId>
    <version>1.5.0</version>
</dependency>

JFreeChart line chart

In the example, we create a line chart showing the average salary per age.

A line chart is a basic type of chart that displays information as a series of data points connected by straight line segments. A line chart in JavaFX is created with the ChartFactory.createXYLineChart().

Here is the complete example to demonstrate creating a line chart with Jfreechart library:

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.block.BlockBorder;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
import org.jfree.chart.title.TextTitle;
import org.jfree.data.xy.XYDataset;
import org.jfree.data.xy.XYSeries;
import org.jfree.data.xy.XYSeriesCollection;

import javax.swing.BorderFactory;
import javax.swing.JFrame;
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Font;

public class LineChartEx extends JFrame {

    public LineChartEx() {

        initUI();
    }

    private void initUI() {

        XYDataset dataset = createDataset();
        JFreeChart chart = createChart(dataset);

        ChartPanel chartPanel = new ChartPanel(chart);
        chartPanel.setBorder(BorderFactory.createEmptyBorder(15, 15, 15, 15));
        chartPanel.setBackground(Color.white);
        add(chartPanel);

        pack();
        setTitle("Line chart");
        setLocationRelativeTo(null);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    private XYDataset createDataset() {

        var series = new XYSeries("2016");
        series.add(18, 567);
        series.add(20, 612);
        series.add(25, 800);
        series.add(30, 980);
        series.add(40, 1410);
        series.add(50, 2350);

        var dataset = new XYSeriesCollection();
        dataset.addSeries(series);

        return dataset;
    }

    private JFreeChart createChart(XYDataset dataset) {

        JFreeChart chart = ChartFactory.createXYLineChart(
                "Average salary per age",
                "Age",
                "Salary (€)",
                dataset,
                PlotOrientation.VERTICAL,
                true,
                true,
                false
        );

        XYPlot plot = chart.getXYPlot();

        var renderer = new XYLineAndShapeRenderer();
        renderer.setSeriesPaint(0, Color.RED);
        renderer.setSeriesStroke(0, new BasicStroke(2.0f));

        plot.setRenderer(renderer);
        plot.setBackgroundPaint(Color.white);

        plot.setRangeGridlinesVisible(true);
        plot.setRangeGridlinePaint(Color.BLACK);

        plot.setDomainGridlinesVisible(true);
        plot.setDomainGridlinePaint(Color.BLACK);

        chart.getLegend().setFrame(BlockBorder.NONE);

        chart.setTitle(new TextTitle("Average Salary per Age",
                        new Font("Serif", java.awt.Font.BOLD, 18)
                )
        );

        return chart;
    }

    public static void main(String[] args) {

        EventQueue.invokeLater(() -> {

            var ex = new LineChartEx();
            ex.setVisible(true);
        });
    }
}

Run above program will produce the below output: